Motorboat

ABSTRACT

A stabilizing tube, fixed to the hull of a boat below the waterline thereof with an inlet and an outlet respectively at the bow and the stern of the boat, has its midsection provided with water-expulsion holes which can be obstructed by a slider and open into the surrounding water to facilitate transverse steering. A rudder is mounted near the outlet end of the tube while a propeller in the tube at its inlet end serves to drive the boat forward or backward. The flow of water through the tube can be blocked by a valve just rearwardly of the expulsion holes.

United States Patent Inventor Gregor Sporri Basel, Switzerland App]. No.842,469 Filed July 17, 1969 Patented Oct. 5, 1971 Assignee Emil WartmannBasel, Switzerland a part interest Priority July 19, 1968 Switzerland 11054/68 MOTORBOAT 3 Claims, 6 Drawing Figs.

US. Cl 115/12, 1 14/122 1111.01 B63h11/00,

1363b 39/00 Field ofSearch 115/12, 14,

Primary ExaminerTrygve M. Blix Att0rneyl(arl F. Ross ABSTRACT: Astabilizing tube, fixed to the hull of a boat below the waterlinethereof with an inlet and an outlet respectively at the bow and thestern of the boat, has its midsection provided with water-expulsionholes which can be obstructed by a slider and open into the surroundingwater to facilitate transverse steering. A rudder is mounted near theoutlet end of the tube while a propeller in the tube at its inlet endserves to drive the boat forward or backward. The flow of water throughthe tube can be blocked by a valve just rearwardly o the expulsionholes.

PAT-ENTEU 0m 5197! SHEET 1 OF 3 PATENTED BET 51971 SHEET 2 [IF 3MOTORBOAT This invention relates to a motorboat having at least onestabilizer tube which is arranged under the waterline substantially inthe longitudinal direction of the boat and substantially horizontal aswell as substantially in a straight line in or on the boat's hull andfirmly connected thereto, also including means adapted to drive waterthrough the stabilizer tube, characterized in that the rudder blade isarranged directly behind the stabilizer tube in the stream expelled fromthe tube, the stabilizer tube being provided substantially in thelongitudinal center of the lateral plane of the boat both on the portside as well as on the starboard side, with water-expelling openingsselectively closable and throttling, means being provided for completelyor partially closing one of the mouth ends of the stabilizer tube.

Propulsion of the boat is then effected on the one hand by the suctionor pulling action at the water inlet mouth and on the other hand by thereacting force of the water column at the outlet mouth of the stabilizertube. With only one stabilizer tube, the same will preferably be ledthrough the body of the boat lengthwise in the middle thereof. On theother hand, with the adoption of several stabilizer tubes, these arepreferably arranged symmetrical with the longitudinal axis of the boat.For dealing with special problems, it is possible to have arrangementsof stabilizer tubes, with the tubes extending symmetrically from the bowtowards the sides of the boat or symmetrically from the sides of theboard towards the stern. Alternatively it is possible to have severalstabilizer tubes arranged one above the other to ensure optimum drivingconditions for different amounts of loading of the boat (differentdraughts).

Moving the boat backwards is achieved by corresponding reversal of themovement of the water column. The steering of the boat is effected by arudder blade arranged immediately behind the stabilizer tube,and'additionally, with the adoption of several stabilizer tubes, byselectively throttling or opening the starboard or port lateralwater-expelling openings.

The adoption of stabilizer tube drives, in conjunction with shippropellers, turbines or pumps, introduces a whole series of advantages,of which the following may be mentioned:

1. Because of the considerable weight of the water present in thestabilizer tube and uniformly distributed along the boats hull, as wellas because of the inertia of the linearly moved water column, the boatis strongly stabilized lengthwise, and receives also a correspondingstabilizing when several stabilizer tubes are arranged symmetrically.

2. A substantial portion of the water otherwise displaced by the bow isled through the body of the boat so as to considerably diminish thehydraulic drag.

3. Because of the uniform expulsion of water at the stem,

the flow conditions become much quieter, with a corresponding diminutionof the wake.

4. Because of the reactive force of the water column confined in aconcentrated jet, a very much shorter braking distance is attained,particularly before obstacles in which the jet impinges (for instancequays).

5. Because of the rudder blade being located in the expelled stream fromthe stabilizer tube, particularly favorable maneuverability is ensured.

6. Because of the drive of the boat being located within the boat and/ortube, the possibility of injuries or damage being caused by floatingbodies is practically excluded.

7. The application of symmetric lateral expelling openings andcorresponding throttle valves on and/or in the stabilizer tube enablesthe boat to move easily transversely, so that it is possible to approachsideways easily to the quay and also to a drowning person withoutdanger.

For this purpose the selectively closable or throttling waterexpulsionopenings in the stabilizer tube both at the port side and starboardside, as well as the device for shutting down the cross-sectional areaof flow entirely or partly, serve to enable the water to flow out asdesired to a great extent or entirely sideways instead of backwards. Thearranging of the lateral water-expulsion openings in the region of thelongitudinal center of the lateral plane of the boat has thus theadvantage that the water-expulsion openings do not emerge from thewater, even when they are heavy waves, so that the action remainsuniform. Another merit of this special arrangement of thewater-expulsion openings in the region of the longitudinal center of thelateral plane is to be seen in the fact that the reactive force of theissuing jet of water exerts no torque tending to turn the board roundits vertical axis, but drives the boat accurately transversely.

The accompanying drawing shows by way of example three forms ofembodiment incorporating the invention therein:

FIG. 1 shows the plan of the boat according to the first form, withcross-sectional profile drawn hatched;

FIG. 2 is an elevation to FIG. 1, with details in vertical section;

FIG. 3 is a plan of the second form of the boat, with crosssectionalprofile drawn hatched;

FIG. 4 shows an elevation to FIG. 3, with details in vertical section;

FIG. 5 is a plan of the third form of the boat, with cross-sectionalprofile drawn hatched, and

FIG. 6 is an elevation corresponding to FIG. 5, with several parts invertical section.

Referring to FIGS. 1 and 2, reference character 1 designates the hull ofa boat or of a motorboat. The bow of the boat houses the motor 2inclined downwards to the front and serving to drive a shaft 4 through agear 3, a screw 5 designed as propeller being arranged on the free endof the shaft. The propeller projects into the interior of a tube 6 whichextends lengthwise of the hull of the boat and passes therethrough underthe waterline WL-WL. Approximately in the longitudinal middle of theboat or of the lateral plane thereof, the stabilizer tube 6 is providedat the port and at the starboard side with additional water-expulsionopenings 9 which can be selectively held open, throttled or evencompletely closed by means of valves l0, 10 arranged at both sides ofthe tube. Said valves are actuated by two hand levers 11,11 which arepivoted to the hull at 12 and are connected with their forked endsthrough linkage to the valves 10,10. Numeral 13 denotes a throttle valvefitted into the stabilizer tube 6; by means of the valve 13 thecross-sectional area of flow of tube 6 can be either throttled orcompletely closed. The throttle valve 13 is actuated by a handwheel 14which is operatively connected thereto through a linkage 15. Finally,numeral 16 denotes the rudder blade which can be turned round a verticalaxis in the longitudinal central plane of the stabilizer tube 6.

Power and movement of the engine 2 are transmitted in the usual mannerthrough gear 3 and the shaft to propeller 5 which draws water in throughthe water inlet 7 at the stem of the boat and expels the water columnpresent in tube 6 against the rudder blade 16 at the outlet 8 at thestern. Propulsion of the boat is effected under the suction action ofpropeller 5, and additionally by the reaction of the column of waterissuing through the stern opening 8 of tube 6.

Should the boat have to be directed transversely during a maneuver, forinstance to port, throttle valve 13 is closed more or less or evenaltogether, and valve 10 at the starboard side is more or less opened.Thus the water drawnin by propeller 6 through stem opening 7 of tube 6is expelled through the starboard openings 9, whereby the boat will bemoved transversely to port. Since the openings 9 for the lateralexpulsion of water are in the longitudinal middle of the lateral planeor in the region of the center of gravity of the lateral plane, the boatwill be moved practically transversely, i.e. perpendicular to itslongitudinal axis.

In the second form as shown in FIGS. 3 and 4, numeral 1 again designatesthe hull of the boat. In contract to the aforementioned example, in theform according to FIGS. 3 and 4 provision is made of two motors 2,2which are connected through two gears 3 and 3' with two driving shafts 4and 4', transmitting their power to two propellers 5 and 5'. Inaccordance with this, two stabilizer tubes 6 and 6' are provided inmirror image arrangement with reference to the boat's longitudinal axis.In the region of the water inlet and water outlet openings 7,8, thestabilizer tubes 6,6 extend lengthwise of the boat. For the sake ofsimplicity, the items 9-15 have been omitted in FIGS. 3 and 4. In otherrespects the handling and action are the same as in the aforedescribedform.

In the further example according to FIGS. 5 and 6, three stabilizingtubes 6,6',6" are arranged. Accordingly, three motors 2,2',2" areprovided, each of which drives a shaft 4,4,4 as well as a propeller5,5',5" through a shaft 3,33".

As in the form according to FIGS. 1 and 2, the lateral waterexpellingopenings 9,9 are provided only in the stabilizer tube 6 disposed in thelongitudinal central plane of the board. In contrast to the example asin FIGS. 1 and 2, in the form according to FIGS. 5 and 6, instead of thetwo valves 10,10 for closing or opening the lateral water outlets 9,9,there is provided one drum 10" which can be turned round itslongitudinal central axis. Said drum is operable by means of a handcrank19 through a chain gear 18 arranged in a casing 17. Also in contrast tothe example as in FIGS. 1 and 2, in the form according to FIGS. 5 and 6,instead of the throttle flap 13, there is arranged a slide valve 13' bymeans of which the cross-sectional area of flow of the stabilizer tube 6can be throttled or shut down completely. 'Raising or lowering of valve13 is brought about by a spindle 21 arranged in a casing and connectedto a handcrank 23 through a chain gear 22. Reference charactersl6,l6,l6" denote three rudder blades disposed in the verticallongitudinal central planes of stabilizer tubes 6, 6', 6". Also in thiscase, the handling and action are the same as in t bodim am t u s-4am Inorder to ensure a good stabilizing effect, the diameter of thestabilizer tube (or tubes) should have a value not less than half thedraught of the boat.

What I claim:

I. A stabilizing system for a boat having a hull, comprising a tubefixed to the hull longitudinally of the boat being the waterlinethereof, said tube having an inlet and an outlet respectively at the bowand the stern of the boat and having a plurality of axially spacedlateral holes in its midsection opening directly into the surroundingwater;

propulsion means adjacent said inlet;

shutter means in said tube intermediate said holes and said outlet forselectively blocking the flow of water through said tube;

a rudder movably connected to the hull and extending outside said tubeadjacent said outlet;

slider means in said tube juxtaposed with said midsection forselectively opening and closing said holes, said slider means havingaxially spaced openings respectively alignable with said holes; and

operating means for axially shifting said slider means between anobstructing and a nonobstructing position.

2. A system as defined in claim 1 wherein said shutter means comprises arotatable valve disk and a lever linked therewith for rotating same.

3. A system as defined in claim 1 wherein said slider means comprises anelongated perforated plate, said operating means including a handleengaging said plate and projecting from said tube.

1. A stabilizing system for a boat having a hull, comprising a tubefixed to the hull longitudinally of the boat being the waterlinethereof, said tube having an inlet and an outlet respectively at the bowand the stern of the boat and having a plurality of axially spacedlateral holes in its midsection opening directly into the surroundingwater; propulsion means adjacent said inlet; shutter mEans in said tubeintermediate said holes and said outlet for selectively blocking theflow of water through said tube; a rudder movably connected to the hulland extending outside said tube adjacent said outlet; slider means insaid tube juxtaposed with said midsection for selectively opening andclosing said holes, said slider means having axially spaced openingsrespectively alignable with said holes; and operating means for axiallyshifting said slider means between an obstructing and a nonobstructingposition.
 2. A system as defined in claim 1 wherein said shutter meanscomprises a rotatable valve disk and a lever linked therewith forrotating same.
 3. A system as defined in claim 1 wherein said slidermeans comprises an elongated perforated plate, said operating meansincluding a handle engaging said plate and projecting from said tube.